1. Field of the Invention
This invention relates to an image forming apparatus which receives image data and forms an image corresponding to the image data on a printing medium.
2. Related Background Art
Conventionally, typical image forming apparatuses such as printers are line printers which print one page while receiving input data line by line, and page printers which print after receiving image data corresponding to one or more entire pages and storing the received data in a memory provided for that purpose. It is conventional that image data is processed page by page (where the page is of a certain fixed size), and the image is formed, on the basis of the image data, on a printing medium such as cut paper or roll paper.
Therefore, when a long, continuous image that is not of some standard length (e.g., one page of a standard size) is printed on the printing medium using a conventional page printer, it is necessary to provide a large memory for storing data corresponding to the image. Further, when such data is stored in a multi-page memory, as in a page printer, the image is not printed continuously.
On the other hand, in a line printer, such an image can be printed while the data is being received, that is, data reception continues during printing. However, for this to be done, the host computer must be occupied in order to communicate with the printer, until the printing ends. If the host computer is occupied for this purpose, especially when the host computer is used to control plural printers, the waiting time for the other printers is inconveniently long, and therefore, the operation of the overall system is not efficient.
In addition to the foregoing problems, it takes a long time to transfer a large quantity of image data from the host computer to an image forming apparatus such as a printer, and thus in such a case it takes longer than desirable to print the image data.